Arc suppression control and methods therefor

ABSTRACT

A device, circuit, system, and method for arc suppression is described. A processor, including an input terminal and an output terminal, is configured to output pulses on the output terminal based on an indication at the input terminal of a separation of a pair of electrical contacts. A contact bypass circuit, coupled to the output terminal and in parallel with the pair of electrical contacts, is configured to provide an electrical bypass between the pair of electrical contacts based on the plurality of pulses as generated by the processor.

PRIORITY

This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/707,373, “ARC SUPPRESSOR,” filed Sep. 28, 2012, which is incorporated herein in its entirety.

This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/788,786, “ARC SUPPRESSOR,” filed Mar. 15, 2013, which is incorporated herein in its entirety.

TECHNICAL FIELD

The present application relates generally to electrical current contact arc suppression.

BACKGROUND

Electrical current contact arcing may have a deleterious effects on electrical contact surfaces, such as of relays and certain switches. Arcing may degrade and ultimately destroy the contact surface over time and may result in premature component failure, lower quality performance, and relatively frequent preventative maintenance needs. Additionally, arcing in relays, switches, and the like may result in the generation of electromagnetic interference (EMI) emissions. Electrical current contact arcing may occur both in alternating current (AC) power and in direct current (DC) power across the fields of consumer, commercial, industrial, automotive, and military applications. Because of its prevalence, there have literally been hundreds of specific means developed to address the issue of electrical current contact arcing.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings.

FIG. 1 is a diagram of a system including an arc suppressor, in an example embodiment.

FIG. 2 is a block diagram of an example of an arc suppressor, in an example embodiment.

FIGS. 3A-D depicts schematic diagrams illustrating example embodiments of arc suppression processors.

FIGS. 4A-4F depicts schematic diagrams illustrating example embodiments of contact bypass circuit.

FIGS. 5A-5C depict waveform diagrams illustrating example embodiments of arc suppressor signal timing.

FIG. 6 depicts waveform diagrams illustrating an example embodiment of arc suppressor operating modes.

FIG. 7 is a flowchart for suppressing an arc, in an example embodiment.

DETAILED DESCRIPTION

Certain examples of arc suppressors, to whatever extent they suppress or purport to suppress arcs, have utilized passive components to suppress the arc. Thus, for instance, RC snubbers, which have been utilized substantially ineffectively in the actual suppression of an arc, may merely include passive components, such as resistors and capacitors, that are not actively engaged in the suppression of an arc. Conversely, certain arc suppressors have utilized active components that are affirmatively turned on or engaged to suppress the arc. However, such arc suppressors may merely turn on for some predetermined period of time without respect to an actual amount of time or activation sequence that may be utilized to suppress the arc. It may, in certain circumstances, be preferable to minimize an amount of time actually engaged in the suppression of an arc.

A processor and contact bypass circuit have been developed that may be utilized in the suppression of an arc over a contact. The processor may receive an indication of a separation of the contact, upon which the processor may output a plurality of pulses to the contact bypass circuit. The contact bypass circuit may provide a bypass over the contact based on the pulses as generated by the processor. In various examples, the pulses may suppress the arc without requiring the contact bypass circuit to be open constantly during an arc duration, over which the arc may tend to form. Limiting a duration of engaging the contact bypass circuit may reduce wear on the contact bypass circuit while also, in various examples, reducing the power that may be utilized to operate the contact bypass circuit in particular and the arc suppressor in general.

FIG. 1 is a diagram of a system 100 including an arc suppressor 102 as disclosed herein. While the arc suppressor 102 will be discussed herein with respect to electrical contacts, it is to be recognized and understood that the arc suppressor 102 may be equally applicable to any of a variety of components and circumstances in which an arc may tend to form, such as physically fixed electrodes and the like. The discussion of the arc suppressor 102 with respect to electrical contacts does not limit the applicable scope of the arc suppressor 102 only to electrical contacts.

The system 100 includes a power source 104, a contact 106, and a load 108. The power source 104 may be an AC power source or a DC power source. Sources for AC power may include generators, alternators, transformers, and the like. The source for AC power may be sinusoidal, non-sinusoidal, or phase controlled. An AC power source may be utilized on a power grid (e.g., utility power, power stations, transmission lines, etc.) as well as off the grid, such as for rail power. Sources for DC power may include various types of power storage, such as batteries, solar cells, fuel cells, capacitor banks and thermopiles, dynamos, and power supplies. DC power types may include direct, pulsating, variable, and alternating (which may include superimposed AC, full wave rectification and half wave rectification). DC power may be associated with self-propelled applications, i.e., articles that drive, fly, swim, crawl, dive, tunnel, dig, cut, etc.

The contact 106 may be a switch, relay, contactor, or other contact. The contact 106 includes a pair of contacts, such as electrodes, as illustrated herein. As noted above, the contact 106 may alternative be a static electrode or electrodes or other component over which an arc may tend to form. The load 108 may be a general purpose loads, such as consumer lighting, computers, data transfer switches, etc. The load 108 may be a resistive load, such as a resistor, heater, electroplating device, etc. The load 108 may be a capacitive load, such as a capacitor, capacitor bank, power supply, etc. The load 108 may be an inductive load, such as an inductor, transformer, solenoid, etc. The load 108 may be a motor load, such as a motor, compressor, fan, etc. The load 108 may be a tungsten load, such as a tungsten lamp, infrared heater, industrial light, etc. The load 108 may be a ballast load, such as a fluorescent light, neon light, light emitting diode (LED), etc. The load 108 may be a pilot duty load, such as a traffic light, signal beacon, control circuit, etc.

In the illustrated example, connection between the power source 104 and the contact 106 is via a non-switched contact current node 110. Connection between the contact 106 and the arc suppressor 102 is optionally via a wire connection 112 affixed to a wire terminal 114 of the arc suppressor 102. Connection between the contact 106 and the load 108 is optionally via a switched contact current node 116. A second connection between the contact 106 and the arc suppressor 102 is optionally via a wire connection 118 affixed to a wire terminal 120 of the arc suppressor 102. Connection between the load 108 and the power source 104 is optionally via a return wire connection 122. Thus, the arc suppressor 102 is connected directly in parallel with the contact 106 to be protected.

The arc suppressor 102 may optionally be coupled to an external power supply via a power supply connection 124. The arc suppressor 102 may further optionally be coupled to an external status monitor via a status monitor connection 126. It is emphasized that, as with various components of the system 100, while the power supply connection 124 and status monitor connection 126 are illustrated, such components are optional and may not be included in various examples of the system 100.

Arc Suppressor Block Diagram

FIG. 2 is a block diagram of an example of the arc suppressor 102. The arc suppressor 102 optionally includes some or all of a contact separation detector 200, an indicator 202, a processor 204, a contact bypass circuit 206, a component protection circuit 208, a protection circuit 210, a connection termination 212, a power connection 214, and a power supply 216. While the contact separation detector 200 disclosed herein may be described with respect to contacts, it is to be understood that the contact separation detector 200 may be applicable to detecting an arc generally without respect to contact separation. Thus, in examples in which the arc suppressor 102 is utilized with respect to components other than contacts, the contact separation detector 200 may be understood as an arc detector or arc condition detector.

The block diagram of the arc suppressor 102 includes elements of the arc suppressor 102 generically and without respect to specific voltage, current or power ratings. In various specific implementations, the various blocks may be scaled according to component ratings such as, but not limited to, resistance, capacitance, inductance, voltage, current, power, tolerance, and transformation ratio, to construct specific arc suppressors.

The contact separation detector 200 may detect a condition indicative of a separation of the contact 106, such as a change in voltage and/or current, as disclosed herein. The condition indicative of the separation of the contacts 106 may more generally be a condition indicative of an arc or a formation of an arc, and circumstances in which the contact separation detector 200 is utilized without respect to contacts may produce a detection and an indication of an arc or a condition indicative of an arc. The contact separation detector 200 may, in various examples, output an analog signal that, at relatively low values, indicates a condition, such as a contact separation state, that may not necessarily result in the bypass of the contacts 106. The contact separation detector 200 may, in various examples, output an analog signal that, at relatively higher values, indicates the formation of an arc, as disclosed herein, that may result in bypassing the contacts 106. The values of those indications may be dependent on the circumstances in which the contact separation detector 200 is applied and may be utilized by one or more of the indicator 202, processor 204, and bypass 206 to variously indicate the separations state of the contact 106, indicate an arc condition over the contact 106, and/or bypass the contact 106, as appropriate.

The contact separation detector 200 may output an indication of the contact separation. As illustrated, the indicator is provided to the processor 204. However, in various examples, the indicator may be provided, alternatively or additionally, to the indicator 202 and/or to the contact bypass circuit 206 without respect to the processor 204. On the basis of receiving the indication, the processor 204 may output a trigger signal to engage the electrical bypass of the contact bypass circuit 206 over the contact 106. Alternatively, the contact bypass circuit 206 may receive the indication directly from the contact separation detector 200 and engage the bypass over the contact 106. By bypassing the contact 106 during at least a portion of the time during which the arc may form or tend to form over the contact 106, the energy over the contact 106 may be reduced to levels that may not produce an arc until the conditions within the contact 106 that may cause an arc have passed or otherwise subsided.

The component protection circuit 208 and the protection circuit 210 may provide protection for the various components within the arc suppressor 102. In various examples, the component protection circuit 208 includes one or more of a varistor, a transient voltage suppressor, and back-to-back Zener diodes coupled in parallel with one or more of the contact separation detector 200, the processor 204, and the contact bypass circuit 206. In various examples, the protection circuit 210 includes one or more of a fuse, a resistor, a circuit breaker, and a fusible link coupled in series with one or more of the contact separation detector 200, the processor 204, the contact bypass circuit 206, and the component protection circuit 208.

The connection termination 212 may be a component of the contact 106 itself and may, in various examples, not be considered a component of the arc suppressor 102. In various alternative examples, the arc suppressor 102 may be considered an integral component of the contact 106. The contact termination 212 may be one or more of wire terminals, a pluggable connector, a card-edge connector, and flying leads. The power connection 214 and power supply 216 may optionally supply power to the arc suppressor 102 as a whole, such as to the processor 204. The power connection 214 may be any one or more of wire terminals, a pluggable connector, a card-edge connector, flying leads, and a power connector. The power supply 216 may be any one or more of a battery, a capacitor, one or more voltage regulators, and one or more power regulators.

The arc suppressor 102 may be implemented according to any of a variety of embodiments of some or all of the blocks 200, 202, 204, 206, 208, 210, 212, 214, 216. While specific embodiments are presented in detail herein, it is to be understood that alternative embodiments may be implemented. The particular embodiments may be configured to provide desired performance characteristics, such as for the circumstances in which the arc suppressor 102 is used. The particular embodiments disclosed herein are for the purposes of example and illustration and are not limiting on the implementations disclosed herein.

Arc Suppression Processor

FIGS. 3A-3D depicts schematic diagrams illustrating examples of arc suppression processors. The processors may be utilized as the processor 204, as disclosed herein. It is to be understood that, for the purposes of this disclosure, the term “processor” may include the electronic devices disclosed herein, whether or not conventionally described as a “processor”, and equivalent devices that may provide the same or similar output as the processors disclosed herein. The processors described herein may be actively powered from a power source. Arc suppressors 102 that do not include a processor as disclosed herein may not necessarily utilize a power source, as disclosed herein.

FIG. 3A depicts a schematic diagram illustrating an example of an arc suppression processor 300 including an analog timer 302. The analog timer 302 may be configured with an input line 304 to receive, from the contact separation detector 200, an indication of contact separation of the contact 106. On the basis of the indication of contact separation, the analog timer 302 may output a signal on an output line 306 that may be utilized by the contact bypass circuit 206 to open a bypass over the contact 106 to suppress an arc in the contact 106.

In an example, the analog timer 302 includes a threshold input terminal 308 and a trigger input terminal 310 that may be configured to set an overall sensitivity to the indication of contact separation. As illustrated, a resistor 312 and capacitor 314 may be selected to set the threshold and trigger sensitivity based on power 316 and ground 318. The threshold and trigger may be selected based on the particular circumstances in which the arc suppressor 102 is being utilized, e.g., the threshold and trigger may be set relatively high for high voltage applications and relatively low for low voltage applications. In an example, the resistor 312 is a ten (10) kiloOhm resistor and the capacitor 314 is a 0.01 microFarad capacitor where power 316 is nine (9) Volts. The output provided by the analog timer 302 will be discussed in detail herein.

FIG. 3B depicts a schematic diagram illustrating an example of an arc suppression processor 320 including a microcontroller 322. The microcontroller 322 may be configured with an input line 324 to receive an indication, from the contact separation detector 200, of contact separation of the contact 106. On the basis of the indication of contact separation, the processor 320 may output a signal on an output line 326 that may be utilized by the contact bypass circuit 206 to open a bypass over the contact 106 to suppress an arc in the contact 106.

As illustrated, the microcontroller 322 includes two output terminals 328, 330. The first output terminal 328 is coupled to a gate 332 of a transistor 334 which, when enabled by a signal from the microcontroller 322, opens the transistor 334 to provide the signal on the output line 326 at a voltage 336 different than the power voltage 316 for the microcontroller 322. The second output terminal 330 may provide an output signal from the microcontroller 322 for another purpose, such as for generating a signal from the indicator 202, as disclosed herein. It is to be recognized and understood that, in various examples, the processor 320 does not necessarily include two output terminals 328, 330 where a second output is not needed. Further, the transistor 334 may not be needed where the voltage of the output signal from the microcontroller 322 does not need to be changed for use, e.g., by the contact bypass circuit 206.

FIG. 3C depicts a schematic diagram illustrating an example of an arc suppression processor 338 including a programmable system on a chip 340. As illustrated, the programmable system on a chip 340 has differential input terminals 342, 344, though it is to be understood that, in various examples, the differential input terminals 342, 344 may be replaced or supplemented with one or more non-differential terminals. The input terminals 342, 344 may receive an input from the contact separation detector 200.

As illustrated, the system on a chip 340 includes two output terminals 346, 348. The first output terminal 346 is coupled to a gate 350 of a transistor 352 which, when enabled by a signal from the system on a chip 340, opens the transistor 352 to provide the signal on the output line 354 at a voltage 356 different than the power voltage 316 for the system on a chip 340. The second output terminal 348 may provide an output signal from the system on a chip 340 for another purpose, such as for generating a signal from the indicator 202, as disclosed herein. It is to be recognized and understood that, in various examples, the processor 320 does not necessarily include two output terminals 346, 348 where a second output is not needed. Further, the transistor 352 may not be needed where the voltage of the output signal from the system on a chip 340 does not need to be changed for use, e.g., by the contact bypass circuit 206.

FIG. 3D depicts a schematic diagram illustrating an example of an arc suppression processor 358 including a digital timer 360. The digital timer 360 may be configured with an input line 362 to receive, from the contact separation detector 200, an indication of contact separation of the contact 106. On the basis of the indication of contact separation, the digital timer 360 may output a signal on an output line 364 that may be utilized by the contact bypass circuit 206 to open a bypass over the contact 106 to suppress an arc in the contact 106.

Contact Bypass Circuit

FIGS. 4A-4F depicts schematic diagrams illustrating examples of contact bypass circuits. Any one or more of the contact bypass circuits disclosed herein may be utilized as the contact bypass circuit 206.

FIG. 4A depicts a schematic diagram illustrating an example of a contact bypass circuit 400 including a bipolar junction transistor (BJT) 402 coupled to a bridge rectifier 404. The bridge rectifier 404 is coupled between terminals 406, 408 which are coupled over the contact 106. Upon receiving a trigger signal, such as from the processor 204, the BJT 402 engages the bridge rectifier 404, providing a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the BJT 402 ceases engaging the BJT 402 and the bridge rectifier 404 ceases providing the bypass.

FIG. 4B depicts a schematic diagram illustrating an example of a contact bypass circuit 410 including a field effect transistor (FET) 412 coupled to a bridge rectifier 404. The bridge rectifier 404 is coupled between terminals 406, 408 which are coupled over the contact 106. Upon receiving a trigger signal, such as from the processor 204, the FET 412 engages the bridge rectifier 404, providing a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the FET 412 ceases engaging the BJT 402 and the bridge rectifier 404 ceases providing the bypass.

FIG. 4C depicts a schematic diagram illustrating an example of a contact bypass circuit 414 including an insulated gate bipolar transistor (IGBT) 416 coupled to a bridge rectifier 404. The bridge rectifier 404 is coupled between terminals 406, 408 which are coupled over the contact 106. Upon receiving a trigger signal, such as from the processor 204, the IGBT 416 engages the bridge rectifier 404, providing a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the IGBT 416 ceases engaging the BJT 402 and the bridge rectifier 404 ceases providing the bypass. FIG. 4D depicts a schematic diagram illustrating an example of a contact bypass circuit 418 including multiple insulated gate bipolar transistors (IGBT's) 420, 422, 424 coupled to a bridge rectifier 404. The bridge rectifier 404 is coupled between terminals 406, 408 which are coupled over the contact 106. Upon receiving a trigger signal, such as from the processor 204, the IGBTs 420, 422, 424 engage the bridge rectifier 404, providing a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the IGBT 416 ceases engaging the BJT 402 and the bridge rectifier 404 ceases providing the bypass. Including multiple IGBTs may provide greater robustness in high voltage and high power systems.

FIG. 4E depicts a schematic diagram illustrating an example of a contact bypass circuit 426 including a silicon controlled rectifier (SCR) 428 coupled to a bridge rectifier 404. The bridge rectifier 404 is coupled between terminals 406, 408 which are coupled over the contact 106. Upon receiving a trigger signal, such as from the processor 204, the SCR 428 engages the bridge rectifier 404, providing a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the SCR 428 ceases engaging the BJT 402 and the bridge rectifier 404 ceases providing the bypass.

FIG. 4F depicts a schematic diagram illustrating an example of a contact bypass circuit 430 including a triac 432. Upon receiving a trigger signal, such as from the processor 204, the triac 432 provides a bypass between the terminals 406, 408 and over the contact 106. Upon the signal ending, the triac 432 ceases providing the bypass.

Signal Timing

FIGS. 5A-5C depict waveform diagrams illustrating examples of arc suppressor signal timing. In various examples, the signals are as received by a contact bypass circuit, such as the contact bypass circuit 206, and may regulate the suppression of arcs within a contact, such as the contact 106.

FIG. 5A depicts timing diagram 500 illustrating an example of a contact cycle of timing of a trigger signal to the contact bypass circuit 206 of the arc suppressor 106. The timing diagram includes a time axis 502 and a variable amplitude axis 504. The time axis 502 includes sections corresponding to an open state 506, a make state 508, a closed state 510, and a break state 512. It is noted that the time axis 502 has been interrupted during the closed state 510.

A contact current waveform 514 shows current through the contact 106. A contact voltage waveform 516 shows a voltage over the contact 106. The trigger single waveform 518 shows trigger signals as received by the contact bypass circuit 206.

In an example, in the break state 512, the flow of current may be interrupted and the contact bypass circuit 206 receives bypass pulses coinciding with the rising edge of the contact voltage, indicating that the contact 106 is opening during the break state 512. In turn, the load current may be re-routed through the arc suppressor 102, thus relieving or substantially relieving the contact 106 of current carrying duty and in doing so preventing or substantially preventing the contact 106 from arcing significantly, in effect suppressing the resulting contact arc.

FIG. 5B depicts a timing diagram 520 illustrating an example of a single trigger signal pulse 522 as receivable by the contact bypass circuit 206. The trigger signal pulse 522 includes a fast rise time on the leading edge 524 of the trigger signal pulse 522 followed by a pulse duration 526 at maximum voltage, followed by a slower rise time on the trailing edge 528.

FIG. 5C depicts a timing diagram 530 illustrating an example of an arc suppression voltage and current timing of the arc suppressor 102. The time axis 532 has been magnified in comparison to the time axis 502. The contact voltage waveform 534 includes a relatively extremely fast risetime, in this example on the order of pico- to nanoseconds. In various examples, voltage slew rates may be of approximately eight (8) kiloVolts or greater. The contact separation detector 200 may be configured to detect such risetimes. In an example, within a few pico- to nanoseconds of the contact 106 breaking, the voltage across the contact 106 may reach the arc voltage which is between, for instance, nine (9) Volts and fifteen (15) Volts, depending on the specific contact material.

In this example, when the arc voltage is reached, the current through the contact 106 multiplied with the arc voltage may produce sufficient energy for a spark to ignite plasma in the contact gap 808 and develop into an arc. The arc may burn, for instance, for about five (5) microseconds before the arc suppressor 102 generates the trigger signal pulse for the contact bypass circuit 206 and subsequently extinguishes the arc by means of bypassing the contact current through the arc suppressor.

An arclet 536 of, for instance, five (5) microseconds in duration may be the result of the arc suppression. Arc suppression duration can, in various examples, be around five hundred (500) microseconds in duration, such as in order to give the contact enough time to travel out of the ignition space. The trigger signal pulse 522 may be risetime controlled at the transition to the open state, such as to reduce a likelihood of the arc suppressor 102 generating the trigger signal pulse based on a spurious signal. After the trigger signal pulse 522 is over the contact gap 808 may still widen and the contact 106 may soon thereafter enter the open state.

FIG. 6 depicts waveform diagrams illustrating an example of arc suppressor operating modes. In various examples, there are five distinctly different two-port arc suppressor-operating modes, such as may be generated by the processor 204 as a trigger signal. Alternatively, various ones of the operating modes may be generated as the indication by the contact separation detector 200. The shape and type of trigger signal pulses may determine a specific operational nature of the arc suppressor 102.

In various examples, as illustrated in a first waveform 600, in “crowbar” mode the current bypass circuit 206 receives a trigger pulse that triggers and holds for the remaining duration of a half cycle of an AC current through the contact 106. When the AC current waveform is near the current zero crossing, the arc may tend to extinguish, allowing the contact bypass circuit to be opened and current to flow through the contact 106.

In various examples, as illustrated in a second waveform 602, in “linear” mode the current bypass circuit 206 receives a trigger pulse with a single bypass ramp starting at low resistance and passing through a linear region of an element, such as a BJT, FET, IBGT, and the like, of the current bypass circuit 206 long enough to extinguish a contact arc.

In various examples, as illustrated in a third waveform 604, in “oscillating” mode the current bypass circuit 206 receives trigger pulses with a burst of low resistance sufficiently long enough to extinguish the contact arc.

In various examples, as illustrated in a fourth waveform 606, in “multi-pulse” mode the current bypass circuit 206 receives a series of trigger pulses with low resistance sufficiently long enough to extinguish the contact arc.

In various examples, as illustrated in a fifth waveform 608, in “single-pulse” mode the current bypass circuit 206 receives a trigger pulse with a low resistance bypass pulse of sufficiently short duration to extinguish the contact arc.

In various examples, the waveforms 600, 602, 604 may have a total duration 610 that is equal or substantially equal to the duration 526 of the arc condition as disclosed above with respect to FIG. 5. Thus, in the example of the waveforms 604, each individual oscillation may occur over the cumulative duration 604.

In various examples, the multi-pulse waveform 606 and the single-pulse waveform 608 may have durations 612, 614 less than the duration 526. In various examples, the durations 612, 614 may be selected such that the waveforms 606, 608 may extinguish the arc without necessarily requiring a duration as long as the duration 526 and/or the duration 610. In the illustrated example, three (3) pulses over a duration 612 approximately one-half the length of the duration 526 may be sufficient for the multi-pulse waveform 606 to extinguish the arc without a secondary arc re-igniting. In the illustrated examples, the single-pulse waveform 608 may utilize a duration 614 of approximately one-third of the duration 526 to extinguish the arc. It is noted and emphasized that the example durations 612, 614 are non-limiting and may be dependent, at least in part, on the particular circumstances in which they are used. In various examples, the durations 612, 614 are any duration less than or approximately equal to the duration 526.

In an alternative example, the multi-pulse waveform 606 may be adaptable to the formation of secondary arc re-ignition. The multi-pulse waveform 606 may perform one or more predetermined individual pulses 616 followed by additional individual pulses 616 on detecting an additional contact separation and/or a re-ignition of the arc, as appropriate. In an example, two (2) predetermined pulses 616 are delivered upon contact separation and/or arc ignition followed by individual additional pulses 616 upon the detection of additional contact separation and/or arc ignition.

In various examples, the individual pulses 616 of the multi-pulse waveform 606 may be of the same or substantially the same morphology. Each pulse may be separated by an equal amount of time. As illustrated, the pulses 616 may be separated by varying amounts of time, such as an amount of time that approximately doubles with each successive pulse 616.

Flowchart

FIG. 7 is a flowchart for suppressing an arc. The flowchart may be applicable to the arc suppressor 102 or to any other suitable circuit or system.

At 700, a plurality of pulses are output on an output terminal of a processor based on an indication at the input terminal of a separation of a pair of electrical contacts. In an example, the plurality of pulses is output for each indication received by the processor. In an example, the processor is configured to output the plurality of pulses according to a predetermined cumulative duration.

In an example, an arc duration is based on at least one of an amount of charge carriers between the pair of contacts being greater than a level at which an arc between the contacts is maintained and an arc being thermodynamically supported between the pair of contacts, and the predetermined cumulative duration of the plurality of pulses is less than the arc duration. In an example, the predetermined cumulative duration is based on a duration between a rising edge of a first one of the plurality of pulses and a falling edge of a last one of the plurality of pulses. In an example, a duty cycle of the plurality of pulses varies during the predetermined cumulative duration.

In an example, the processor is configured to output the plurality of pulses according to a predetermined number of pulses. In an example, each one of the plurality of pulses has a substantially equal pulse duration from a rising edge to a falling each of each one of the plurality of pulses. In an example, the processor is at least one of an analog timer, a digital time, a microcontroller, and a system on a chip.

At 702, an electrical bypass is provided with a contact bypass circuit between the pair of electrical contacts based on the plurality of pulses as generated by the processor. In an example, the bypass circuit is configured to provide the electrical bypass a number of times corresponding to a number of pulses of the plurality of pulses.

Additional Examples

The description of the various embodiments is merely exemplary in nature and, thus, variations that do not depart from the gist of the examples and detailed description herein are intended to be within the scope of the present disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure.

In Example 1, an electrical circuit or system includes a processor, including an input terminal and an output terminal, configured to output a plurality of pulses on the output terminal based on an indication at the input terminal of a separation of a pair of electrical contacts and a contact bypass circuit, coupled to the output terminal and in parallel with the pair of electrical contacts, configured to provide an electrical bypass between the pair of electrical contacts based on the plurality of pulses as generated by the processor.

In Example 2, the electrical circuit of Example 1 optionally further includes that the plurality of pulses is output for each indication received by the processor.

In Example 3, the electrical circuit of any one or more of Examples 1 and 2 optionally further includes that the bypass circuit is configured to provide the electrical bypass a number of times corresponding to a number of pulses of the plurality of pulses.

In Example 4, the electrical circuit of any one or more of Examples 1-3 optionally further includes that the processor is configured to output the plurality of pulses according to a predetermined cumulative duration.

In Example 5, the electrical circuit of any one or more of Examples 1-4 optionally further includes that an arc duration is based on at least one of an amount of charge carriers between the pair of contacts being greater than a level at which an arc between the contacts is maintained and an arc being thermodynamically supported between the pair of contacts, and that the predetermined cumulative duration of the plurality of pulses is less than the arc duration.

In Example 6, the electrical circuit of any one or more of Examples 1-5 optionally further includes that the predetermined cumulative duration is based on a duration between a rising edge of a first one of the plurality of pulses and a falling edge of a last one of the plurality of pulses.

In Example 7, the electrical circuit of any one or more of Examples 1-6 optionally further includes that a duty cycle of the plurality of pulses varies during the predetermined cumulative duration.

In Example 8, the electrical circuit of any one or more of Examples 1-7 optionally further includes that the processor is configured to output the plurality of pulses according to a predetermined number of pulses.

In Example 9, the electrical circuit of any one or more of Examples 1-8 optionally further includes that each one of the plurality of pulses has a substantially equal pulse duration from a rising edge to a falling each of each one of the plurality of pulses.

In Example 10, the electrical circuit of any one or more of Examples 1-9 optionally further includes that the processor is at least one of an analog timer, a digital time, a microcontroller, and a system on a chip.

In Example 11, a method includes outputting, with a processor including an input terminal and an output terminal, a plurality of pulses on the output terminal based on an indication at the input terminal of a separation of a pair of electrical contacts and providing, with a contact bypass circuit in parallel with the pair of electrical contacts, an electrical bypass between the pair of electrical contacts based on the plurality of pulses as generated by the processor.

In Example 12, the method of Example 11 optionally further includes that outputting the plurality of pulses includes outputting the plurality of pulses for each indication received by the processor.

In Example 13, the method of any one or more of Examples 11 and 12 optionally further includes that providing the electrical bypass includes providing the electrical bypass a number of times corresponding to a number of pulses of the plurality of pulses.

In Example 14, the method of any one or more of Examples 11-13 optionally further includes that outputting the plurality of pulses includes outputting the plurality of pulses according to a predetermined cumulative duration.

In Example 15, the method of any one or more of Examples 11-14 optionally further includes that an arc duration is based on at least one of an amount of charge carriers between the pair of contacts being greater than a level at which an arc between the contacts is maintained and an arc being thermodynamically supported between the pair of contacts, and that the predetermined cumulative duration of the plurality of pulses is less than the arc duration.

In Example 16, the method of any one or more of Examples 11-15 optionally further includes that the predetermined cumulative duration is based on a duration between a rising edge of a first one of the plurality of pulses and a falling edge of a last one of the plurality of pulses.

In Example 17, the method of any one or more of Examples 11-16 optionally further includes that a duty cycle of the plurality of pulses varies during the predetermined cumulative duration.

In Example 18, the method of any one or more of Examples 11-17 optionally further includes that outputting the plurality of pulses includes outputting a predetermined number of pulses.

In Example 19, the method of any one or more of Examples 11-18 optionally further includes that each one of the plurality of pulses has a substantially equal pulse duration from a rising edge to a falling each of each one of the plurality of pulses.

In Example 20, the method of any one or more of Examples 11-19 optionally further includes that the processor is at least one of an analog timer, a digital time, a microcontroller, and a system on a chip.

The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments. These embodiments are also referred to herein as “examples.” Such examples may include elements in addition to those shown and described. However, the present inventor also contemplates examples in which only those elements shown and described are provided.

All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The above description is intended to be, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. 

What is claimed is:
 1. An electrical circuit, comprising: a processor; and a contact bypass element, coupled to the processor and in parallel with a contact, configured to operate in a multi-pulse mode, wherein the current bypass element triggers with a series of timed pulses sufficiently long to extinguish an arc over the contact. 